Limerick man McCabe was shot dead by republicans during a botched post office raid in Adare in June 1996.

Republican leader Adams told the Irish parliament that the death of detective Donohoe had provoked memories of the killing of Garda McCabe and the wounding of his colleague Ben O Sullivan.

He said: “I want to apologise to Mrs Anne McCabe and the McCabe family, and to Garda (police officer) Ben O’Sullivan and to the families of other members of the state forces who were killed by republicans in the course of the conflict.

“I am very sorry for the pain and loss inflicted on those families. No words of mine can remove that hurt. Dreadful events cannot be undone.